Much attention has been given in recent years to systems used in retail stores for displaying the prices of goods. While manual marking of the prices at the location of the goods, or on the goods themselves, is conventional, attempts have been made to use electronic means instead for displaying the prices at the goods location.
In an experimental stage, some electronic pricing systems employ price tags, also sometimes called modules or labels, each having a display which is typically of a liquid crystal type. One or more data buses are used in such systems to connect many thousands of the labels to a central computer allowing the latter to communicate with particular ones of the labels, e.g. to direct changes in their displayed prices. To this end, the labels are equipped with connectors so that they can be snapped onto one of many locations along rails running along the edges of the store shelves. The connectors electrically connect the labels to buses running along the rails to the central computer.
Experience has shown that physical placement of products within a store has, oftentimes, enormous influence on the sales of the products. Factors including shelf height for a product, and the number of product facings along a shelf can be of great significance to store planners. Thus, it is important for a store planner to ensure that the "plan-o-gram" of the store, which is a plan showing product locations on shelves, is faithfully followed. However, deviations from the plan-o-gram could often result from accidental or intentional misplacement of the labels by store personnel, by customers, or by others.
Attempts have been made to detect misplacement of electronic price display labels so as to remedy it effectively. One such prior art attempt involves the use of an individual electronic controller serving each rail. Nevertheless, such an expedient can, at best, detect misplacement only if a tag has strayed so far as to be on a rail served by another controller. Besides requiring a large number of controllers in a given installation and being ineffective to detect misplacement to a different location on the rail served by a given controller, such systems require that individual labels perform many of the communication transactions, requiring more complex, and thus costly, electronic components.
Accordingly, it is desirable to have an electronic price display system in which detection of a misplacement of a label and communication with the central computer can be carried out effectively and expeditiously.
Those familiar with modern supermarket operations will also appreciate that from time to time it is desirable that store personnel have information other than price regarding store items, quickly and conveniently available. That is, it would be desirable if store personnel could controllably cause a label, or a group of labels in a section, or "subarea" of the store, to show some data other than price regarding each item of merchandise. For example, though product scanning at the checkout counter permits most store items to be reordered automatically, it is nonetheless helpful for personnel to be able to walk the aisles of the store to identify visually any items that require reordering or restocking from the back room of the store. Shoplifting and other forms of inventory shrinkage, for example, can give rise to a disparity between the expected stock (defined as the difference between the amount of product shipped to the store and the amount of product sold at the checkout counter) and actual stock physically present in the store. It would be desirable to have a means whereby the labels would display in numerical terms the number of cases of the product that are in the back room. Where the shelf is bare and the back-room case count is small or zero, personnel can initiate an exceptional reordering of product. Where the displayed back-room case count is at odds with the actual case count in the back room, other corrective action may be taken. It is further desirable that the shift to an alternative display of information be confined to particular subareas, so that the in the remainder of the store the price information usually available to customers continues to be visible.